There is some information in the manual:PinoutsPin 1 RS232 Level Shutdown: +12 VDC signal held for 5 seconds on this pin shuts Patriotdown 120 seconds later. The UPS restarts after 15 seconds when utility power returns.Pin 2 Unused.Pin 3 Normally Open On-Battery Contact: A normally open contact that closes 15 seconds(pulls to Common) after the UPS switches to battery power.Pin 4 Common: The signal ground for all signal pins.Pin 5 Normally Open Low-Battery-Alarm Contact: A normally open contact that closes(pulls to Common) during a Low Battery Alarm.Pin 6 Normally Closed Low-Battery-Alarm Contact: A normally closed contact that opens(releases from Common) during a Low Battery Alarm. This tells some shutdownsoftware when to start a computer shutdown.Pin 7 Unused.Pin 8 Normally Closed On-Battery Contact: A normally closed contact that opens15 seconds (releases from Common) after the UPS switches to battery power.Pin 9 Unused.Contacts consist of open collector circuits capable of switching up to +30 VDC, 6 mA resistiveload.